1. Field of the Invention
This invention relates to a method for manufacturing fine powder for strontium zirconate, SrZrO.sub.3, which is one of dielectric materials.
2. Description of the Prior Art
In recent years, manufacture of fine powder of ceramic materials has been studied and developed from different angles. One of the applications of the finely divided ceramic materials is an application to ceramic capacitors. The recent trend of electronic articles is towards compactness and high performance. Capacitors which are one of important parts of the articles are naturally required to be small in size and light in weight with large capacitance and improved high frequency characteristic. In order to satisfy the requirements, there is recently an increasing demand of multilayer ceramic capacitors. For the manufacture of the multilayer ceramic capacitors, there are needed ceramic materials which have high dielectric constant and are in the form of powder having a fine and uniform size.
Finely divided ceramic materials may be applied not only to the above-described ceramic capacitors, but also to the optical fields.
One of known ceramic materials used for the above purposes strontium zirconate, SrZrO.sub.3. Fine powder of the strontium zirconate has been heretofore produced, for example, by a procedure which comprises mixing powders of strontium carbonate, SrCO.sub.3, and zirconium oxide, ZrO.sub.2, molding the mixture under pressure, subjecting the molded mixture to solid phase reaction at about 1400.degree. C., and mechanically pulverizing the resulting product to obtain a fine powder. The fine powder of SrZrO.sub.3 obtained by the above procedure is disadvantageous in the large and nonuniform size thereof. According to the above method, the particle size is classified by sieving, with the attendant drawback that impurities are inevitably incorporated therein in relatively large amounts along with coarse particles. Aside from the above method, several methods are known including an alkoxide method, an oxalate method, and the like. These methods involve the problem of high production cost.